chore(debug): add Layer 2 — mini Zustand-store + dispatch toggles

Test of SSE-event → store → render-pipeline werkt buiten de Solo
Paneel context. Mirrort het patroon van solo-store maar minimaal.

- debug-store.ts: kleine Zustand-store met tasks + applyEvent +
  applyCount/skipCount-tellers
- store-panel.tsx: rendert store-state in een tabel met statuskleuring
- client.tsx: drie layer-toggles (dispatch / flushSync / startView-
  Transition) + lift dispatch in onmessage. Zo kunnen we elke
  combinatie isoleren

Bevestigd: alle drie de toggles werken op het bare /debug-realtime
endpoint. Volgende laag is Server Action revalidation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/debug-realtime/debug-store.ts

@@ -0,0 +1,71 @@
+// Mini Zustand-store voor de debug-pagina. Mirrort het patroon van
+// stores/solo-store.ts maar dan minimaal: alleen tasks-record + applyEvent.
+// Doel: testen of de SSE-event → store → component-render keten werkt
+// zonder de complexiteit van de echte Solo Paneel.
+
+import { create } from 'zustand'
+
+export interface DebugTask {
+  id: string
+  status: string
+  title: string
+  story_id: string
+  updated_at: string
+}
+
+export interface DebugRealtimeEvent {
+  op: 'I' | 'U' | 'D'
+  entity: 'task' | 'story'
+  id: string
+  story_id?: string
+  task_status?: string
+  task_title?: string
+  debug?: boolean
+  emitted_at?: string
+  [key: string]: unknown
+}
+
+interface DebugStore {
+  tasks: Record<string, DebugTask>
+  applyCount: number
+  skipCount: number
+  applyEvent: (event: DebugRealtimeEvent) => void
+  reset: () => void
+}
+
+export const useDebugStore = create<DebugStore>((set, get) => ({
+  tasks: {},
+  applyCount: 0,
+  skipCount: 0,
+
+  applyEvent: (event) => {
+    if (event.entity !== 'task') {
+      set((s) => ({ skipCount: s.skipCount + 1 }))
+      return
+    }
+    if (event.op === 'D') {
+      set((s) => {
+        const next = { ...s.tasks }
+        delete next[event.id]
+        return { tasks: next, applyCount: s.applyCount + 1 }
+      })
+      return
+    }
+    // INSERT/UPDATE — schrijf altijd, ongeacht of de task al bestond
+    set((s) => ({
+      tasks: {
+        ...s.tasks,
+        [event.id]: {
+          id: event.id,
+          status: event.task_status ?? get().tasks[event.id]?.status ?? '?',
+          title: event.task_title ?? get().tasks[event.id]?.title ?? '(no title)',
+          story_id: event.story_id ?? get().tasks[event.id]?.story_id ?? '?',
+          updated_at: new Date().toISOString(),
+        },
+      },
+      applyCount: s.applyCount + 1,
+    }))
+  },
+
+  reset: () => set({ tasks: {}, applyCount: 0, skipCount: 0 }),
+}))